Abstract #1618

Deng J, Omary R, Larson A, Rhee T, Woloschak G, Paunesku T

Diffusion-weighted magnetic resonance imaging (DW-MRI) techniques permit quantitative in vivo measurement of local water diffusion characteristics within tissues. Multiple studies have demonstrated using DW-MRI to detect early changes in tumor tissue diffusion properties predictive of therapy response. However, most of these studies assumed mono-exponential decay characteristics primarily sensitive to high-mobility extracellular water populations. Recent studies in murine breast cancer models and clinical brain metastases demonstrated bi-exponential diffusion decay properties within tumors. DW-MRI over a wider range of b-values permits derivation of two-compartment diffusion components and interrogation of both low-mobility (intra-cellular or bound water molecules) and high-mobility (extra-cellular) water populations. In this study we performed conventional and high b-value diffusion weighted imaging in the VX2 rabbit tumor model commonly used to evaluate liver tumor therapies. The purpose of this study was t